6" Dredge Project underway

[AUAlaska]

I have been collecting parts all winter to build my 6" dredge, started the build today. I got a old keene 8" for cheap last fall, it came with the 8" triple box and also a 5" triple box. So my plan is to use the parts to build a 6" because I do not want to change my 5 year plan of operation I have on my claims to use an 8" I em able to use a 6" tho. My idea is to use the 8" frame / Floats and the 5" triple box and convert the box from a 5" crash box to a 6" jet flare. the boxes are a 20" x 40" center with 2x 10" x 46" side boxes. I looked at keene and they did not have a 6" jet flare 20" wide but I did find one at DK Nugget, I got the Jet Log from keene (not oversized) to fit the DK flare. I spent today straightening the old frame and sanding it in spots. I will be painting the frame with POR-15 direct to metal rust preventing paint (awesome stuff) The motors are 2x Honda GX270 9.0hp with 4x3 keene pumps. I also got a Gast PCA-10 I will be rebuilding to use on this dredge, I have never used a twin piston so I will have questions for you guys, I have always used T-80's. here are a few pic's:

 

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[AUAlaska]

I got the long runners sanded where there was rust, straighten them out as needed and started paint.

 

[N-Lionberger]

I'm also going to rebuild my first Gast. Looks like a great project .

 

[Reed Lukens]

Why not just use the 8" as is and reduce the nozzle intake to 6"? That makes it a legal 6" dredge...

 

[AUAlaska]

I thought about that and it came down to a few things, one is the weight of the 8" box and accessories plus I sold the eight box and nozzle for good money and lastly I got 2x 9hp motors, I dont believe that would cut it for an 8". But mainly I dont want to lug the big box hose ect. Here is a pic of the 8" I had, its huge Oh and it did not come with hose, lol cant afford 8" hose LOL

 

[AUAlaska]

It's been raining all week but I got the rails for the frame just about done.

 

[principedeleon]

This is why i build most of my pieces myself. .. well i design them and pay someone to weld them.

Buying everything commercially is pretty expensive.
Reasons to build your own. .

Could make your own lighter smaller sluice.
All gold is found in a foot of sluice. .

Building your own jet could be better then buying one because you could tune it with your pump. . Higher Psi Or Less Psi pump like The P350 kind.

It seems like you going to dredging in the sea so you might be better off with the heavy floatation. .

But if you want you could upgrade to aluminum rails sometime in the future.

Hope i gave you something to think about. .

 

[AUAlaska]

More progress!

 

[N-Lionberger]

Gonna be a beast!

 

[AUAlaska]

More pic's

 

[AUAlaska]

I'm also going to rebuild my first Gast. Looks like a great project .

Here is what I have to work with.

I got a new case for it and check valve for it

Also got the snorkel kit for it

I just today ordered the rebuild kit and replacement fan from Armadillo Mining Co, I order most of my stuff from them. Here is the mock up:

 

[AUAlaska]

Slow going, thought I would be farther along but I had to change the frame bars and rethink the Jet flare angle a few times.

Cutting crashbox




Taking sluice apart

 

[AUAlaska]

 

[AUAlaska]

Mock up

 

[Reed Lukens]

With the pumps that high out of the water, they will lose a lot of their power. Definitely make a test run because that's going to be too much floatation for the pumps, taking everything way up out of the water. You may end up pulling the center pontoons out to get it back down low enough to run. Unfortunately a friend learned this the hard way... and had to cut his hose down to 12' to get his dredge to run marginally with the 9hp motors.

 

[AUAlaska]

With the pumps that high out of the water, they will lose a lot of their power. Definitely make a test run because that's going to be too much floatation for the pumps, taking everything way up out of the water. You may end up pulling the center pontoons out to get it back down low enough to run. Unfortunately a friend learned this the hard way... and had to cut his hose down to 12' to get his dredge to run marginally with the 9hp motors.

Is there a set or ideal height from water level? And to fix take out middle floats and add weight or semi flood floats?

 

[jsurddy]

You could build a cabin on top to add weight if you need.

 

[AUAlaska]

I'm trying to figure Luke's comment out about the pumps. Keene sold this frame/floats and it works for other builds. I have 2 gx270 9hp with 3x4 pumps, from keenest web page it said one of them is 450gph w/120 feet of head, I'm running 2, seems like I could be over kill on pump power since keene sells a 6" with 2x 5.5hp and in water my pumps will be a max of 12" out of water, with a rock or two I could get that to 8-9"... I must be missing something, help please

 

[winners58]

my thinking is not necessarily the pumps but how high above the water going into the sluice is where you lose suction power.
how is it going to behave with the weight of the water flowing through the sluice, more than likely raise the pump end even higher.
on my 5" I have a 4x3 on 11hp Brigg's its over a foot off the water I have 26' of hose, the deepest I've been is about 20' I didn't
notice any change in suction, but I lowered my sluice so my flair is only 4" off the water when running.
I'd say yours is going to be a balancing act that will need to be tuned in to get the bugs out. try it out close to home first...
my 5" dredge running, https://m.youtube.com/watch?v=GYWXM--VAVA

 

[mendoAu]

Just a couple of things. First, I used to live in a mobile home park with a swimming pool....great friends with the manager and she let me use the pool to set my dredge up to fine tune...etc. so it was only a five minute trip to the "test site". Second, I'd cut and weld that second crossmember from the front with a hump in the middle so if you need to you can raise the flair up a bit, I notice that it is hitting the crossmember as it sits. Third, the ONE big thing is to have the back of the sluice slightly above the water level and go from that point on for angle and "droppage" for the rest of the system. Fourth, what I think that was mentioned about the height of the intake foot valves is that if the screen is not deep enough it will tend to "whirlpool" and suck some air...a big power loss. A couple of things would be to cut the footvalves and extend them down with some ABS pipe pieces a couple of inches or as much as needed. Don't try to use elbows or similar at the top 'cause the fill tube will be to low to fill the pumps correctly. Or you could sell those yellow footvalves and just go with hose and "standard" footvalves that can be cut to any length you need. It is nice to fill those yellow ones and not have to deal with "pumping up" those standard valves but if you get quality footvalves they should hold water well and not need to be messed with for days. Check out how high the pump is in this picture...
Keene Engineering, Inc,
And finally, I can't really see how you attached the flair to the box but if you cut slots where it attaches and use bolts,washers and wingnuts it will allow you to adjust the angle that your flair shoots into the sluice, to high...no good (heavies won't drop fast enough to catch in your upper riffles), to low (will tend to blow heavies out and past your upper riffles)...no good.
And with those engines/pumps you shouldn't have any "power" problems....in fact it will suck yur' head right up the hose if ya ain't careful..HA!